Zurich: Switzerland said Wednesday it has amended a decree to ensure that US clients of Swiss banks are informed of any probes against them, against a backdrop of increased action by Washington.

"The amendment should ensure that the procedural rights of affected persons domiciled in the United States remain guaranteed even if administrative assistance requests are submitted based on certain patterns of behaviour," aid the Swiss finance ministry said in a statement.

Concerned banks targetted by such administrative requests would now be required to inform their clients that they are being investigated.

In cases where the bank is unable to identify the account holder or inform the individual of the probe, it is up to the Swiss authorities to inform the individual through a publication in the Federal Gazette.

According to Swiss law, anyone targetted by a request for administrative assistance by a foreign authority can appeal against the transfer of his or her details.

Eleven Swiss banks, including Credit Suisse, Julius Baer and Zuercher Kantonalbank are currently being investigated by US authorities for allegedly helping Americans to evade taxes.

In relation to the probe, Bern has been transmitting details of US clients to the US tax authorities, according to Swiss media.